Who knows forty-two?
Please cite/link your sources, if possible. At some point in the next few days, I will:
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42 travels (of B'nei Yisrael) in the Torah.
מ״ב מסעות בתורה רעמםם סוכות איתם כו׳ במדבר ל״ג
42 details in the Menorah. (22 "cups", 11 "globes", 9 flowers)
מ״ב דברים במנורה כ״ב גביעים י״א כפתורים ט׳ פרחים
42 are the minimum (and today, pretty much the standard) customary number of lines per column in a Torah scroll. (Shulchan Aruch, Yoreh De'ah 275:6 in Hagah)
42 are the years during which the royal houses of the Judean and Israelite (Ten Tribes) kingdoms were related by marriage.
This was displeasing to Hashem, since the former were righteous and the latter were not (and indeed, some of the Judean kings became corrupt under their in-laws' influence). The result was that almost all of David's descendants were wiped out, with only one infant (Yehoram) being spared. (Seder Olam Rabbah ch. 17, explaining II Chron. 22:2 - cited in the commentaries ad loc.)
42 occurences of the name of Hashem in both tefillin.
מ״ב אזכרות בתפלין של יד ושל ראש כ״א בד׳ פרשיות
The number of words in אנא בכח.
42 cities of refuge which did not give refuge to the unintentional killer without his awareness (Makkos 10a).
Rus Rabah 2:8 says that the fellow that was watching the reapers in Boaz's field, was watching 42 reapers.
The number of words in birkas hatzadikim in Sh'monah Esre (according to the סידורים of the word-counting genre)
42 is the source.
(V'dibarta Bam= 42)
The Or HaChaim HaKadosh brings 42 elucidatioms on the beginning verse of Bechukosai.